Fire protection system



June 30, 1964 c. J. RENDA 3,139,143

FIRE PROTECTION SYSTEM Filed July 27, 1962 2 Sheets-Sheet l CONTQOL.AMPLIFIEQ INVENTOR. Carmen c]. Pena/a [WWW ATTORNEY.

June 30, 1964 c. J. RENDA 3,139,143

FIRE PROTECTION SYSTEM Filed July 27, 1962 2 Sheets-Sheet 2 J g A l?INVENTOR. CarmendPe/vaa UESQQQ Q 3 Ekb W \h m l t-l Q Q2806 9 +0$$$QQ Qcsacaw ATT RNEY.

United States Patent 3,139,143 FREE PROTECTEON SYSTEM Carmen J. Renda,Youngstown, Ghio, assignor, by mesne assignments, to Automatic SprinklerCorporation of America, Youngstown, Ohio, a corporation of Ohio FiledJuly 27, 1962, Ser. No. 212,963 7 Claims. (Cl. 1169-19) This inventionrelates to a fire protection system and more particularly to a systemcapable of extremely fast detection of fire and minimum time lapse indelivering an extinguishing agent on the fire.

The principal object of the invention is the provision of a fireprotection system that will detect fire and deliver a fire extinguishingagent on the fire in the elapsed time range of a few milliseconds.

A further object of the invention is the provision of a fire protectionsystem in which the detection apparatus includes sensors instantaneouslyresponsive to predetermined wave lengths in the electromagnetic spectrumwhich are characteristic of combustion of the material being protected.

A still further object of the invention is the provision of a fireprotection system that includes electronic sensor units in its detectionsection and a responsive electronically actuated self-powered valve inits extinguishing agent controlling section.

A further object of the invention is the provision of a fire protectionsystem capable of detecting a fire and delivering a fire extinguishingagent on the fire in a few milliseconds to effectively control a fire inan extremely hazardous material such as rocket propellants and similarself-oxidizing materials.

A still further object of the invention is the provision of a fastacting fire protection system designed for hazards where utmost speed isessential for effective fire control and in which the fire detectionapparatus utilizes photoconductors so designed as to discriminatebetween certain portions of the electromagnetic spectrum and wherein thedetectors are arranged in a balanced system to insure desirableresponse.

The fire protection system disclosed herein was conceived specificallyfor flash fire suppression. Where speed is of the utmost importance, asystem capable of operating in the milliseconds range is needed todetect and extinguish fire at its very inception. The presentlydisclosed system accomplishes this primary object by utilizingelectromagnetic detection which is arranged to respond to a portion ofthe electromagnetic spectrum as is produced by the burning of thematerial protected. A control unit comprising a portion of the systemprovides convenient connections between the detecting system and theextin guishing agent delivery portions of the system and providescontinuity tests for the detection and actuation circuits connectedtherethrough. The fast acting valve controlling the fire extinguishingagent is operated by electronic detonation of an explosive charge whichunlatches the clapper allowing the extinguishing agent to flow from theapplicators. The system is so designed and arranged that it utilizesfully primed piping so that the extinguishing agent is at theapplicators ready to flow when the system is actuated. Alarm signalssuch as horns, sirens, bells, lights, etc., may be added as desired. Thesystem is arranged to be responsive to fire in the material protectedand additionally to guard against false response to normally presentelectromagnetic spectrum sources.

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts and in the details of construction hereinafterdescribed and claimed, it being the intention to cover all changes andmodifications of the example of the invention herein chosen for purposesof the disclosure, which do not constitute departures from the spiritand scope of the invention.

The invention is illustrated in the accompanying drawing, wherein:

FIGURE 1 is a schematic view of the complete fire protection system.

FIGURE 2 is a symbolic diagram of the electromagnetic detection portionsof the fire protection system illustrated in FIGURE 1.

FIGURE 3 is a symbolic diagram of the control amplifier portion of thefire protection system. illustrated in FIGURE 1.

FIGURE 4 is a symbolic diagram of a time delay testing circuit used inconnection with the control amplifier shown in FIGURE 3.

By referring to the drawings and FIGURE 1 in particular, a symbolicillustration of the fast acting fire protection system may be seen. Thesupervised area having the hazard to be protected is located at A. Fireextinguishing agent applicators 10, 10 are arranged adjacent thereto anddirected thereon and the applicators 10, 10 are preferably nozzles withblow-out plugs. One or more sensors 11 are adjustably positioned asclose to the hazard area A as practical. The applicators 10 are incommunication with extinguishing agent supply piping 12 which in turncommunicates with a fast acting deluge valve 13 which is of theexplosive charge actuated type and which in turn is in communicationwith an extinguishing agent supply pipe 14. The explosive charge bywhich the fast acting valve 13 is operated is disclosed in theco-pending application for patent of Wayne E. Ault, Serial No. 200,122and as disclosed therein and in FIGURE 1 hereof, the explosive charge isactuated by an electrical circuit 15 which is illustrated and indicatedas a double conductor cable connecting the explosive actuated portion 16of the valve 13 with a control amplifier generally indicated at 17.

Still referring to FIGURE 1 of the drawings, it will be seen that thesensor 11 which is shown in operative relation to the hazard area A isan infrared detector and comprises a solid state type of photoconductorso designed as to discriminate between certain electromagnetic waves. Asused herein the electromagnetic wave sensor'will respond to the nearinfrared area of such electromagnetic waves. The sensor 11 includesthree units arranged to form a voltage divider and is electricallyconnected at a signal takeoff point as hereinafter described to thecontrol amplifier 17 by a multiple conductor cable '18. The controlamplifier 17 is supplied with suitable energy from a power source 19 byway of conductors 20.

In addition to the sensor 11 positioned in proximity to the hazard areaA, one or more heat actuated devices 21 are positioned in proximitythereto and in communication with tubing 22 which extends to anelectrical control 23. The electrical control 23 is a device heretoforeknown in the art in which an air pressure actuated diaphragm controls anelectric switch so that fire in the area of the heat actuated devices 21will increase air pressure in the heat actuated device 21, the tubing 22and act to move the diaphragm and close the electric switch in theelectrical control 23 and thereby close an electric circuit comprising atwo-conductor cable 24 which in turn communicates with the controlamplifier 17.

In the unlikely event of the failure of the sensor 11 to actuate thesystem, the heat actuated devices 21 will provide the necessaryactuation and the positive operation of the fire protection system isthus assured.

, It will thus be seen that fire in the hazard area A will result in theoperation of the fast acting valve 13 and the delivery of the fireextinguishing agent through the primed piping 12 of the applicators 10in the matter of milliseconds and such speeds are effectively used inextinguishing fires in materials or fuels containing their own oxidizingagents where the control of the fire is occasioned by lowering thetemperature to a point below that necessary for ignition.

The principal point of novelty in the present fire protection system isthe electromagnetic detecting and actuating circuitry and the sensors 11which comprise part of it, and which circuitry operates at electronicspeeds to open the extinguishing agent control valve 13 in millisecondsmaking possible the efliective control of fire in extremely hazardousmaterials.

By referring now to FIGURE 2 of the drawings, a symbolic diagram of theelectromagnetic system may be seen and it will be observed that two ofthe sensors 11 are illus trated as being electrically connected bymulticonductor cables to a terminal strip 25 which in the exampleillustrated includes twelve numbered terminals. One of the sensors 11has four-circuit wires connected to numbered terminals 1, 2, 9 and 11while the other sensor 11 has its four circuit wires connected to thenumbered terminals 1, 3, 8 and 11. The conductors extending from thefirst sensor, the uppermost one as seen in FIGURE 2 of the drawings,includes a signal conductor 1 connected with numbered terminal 2; a testconductor 1 connected with numbered terminal 9 and the other sensor 11includes a conductor indicated as signal 2 connected to numberedterminal 3 and a conductor labeled test 2 connected with numberedterminal 8. It will be observed that another sensor can be connected tonumbered terminals 4 and 7 so that three sensors can be connected to theterminal strip 25.

The numbered terminals 2, 3 and 4 are directly connected with thecontrol amplifier 17 and by referring to FIGURE 3 of the drawings, asymbolic diagram of the same may be seen, it being observed that thediagram includes the representation of one of the sensors 11 whichincludes a photoresistor marked blue, a photoresistor marked red and aphotoresistor marked compensator and that the current flow is fromreference point 26 through the photoresistors marked blue, red andcompensator to a reference point 27. Conductors 28 and 29 are connectedto the respective reference points 26 and 27. A signal takeoff pointindicated by reference numeral 30 is lo catedadjacent the photoresistormarked red, and those skilled in the art will realize that these threephotoresistors form a voltage divider. As photons of different wavelengths fall on the photoresistors, the voltage at signal takeoff point30 will vary. A resistor 31 is connected between a lead 32 in connectionwith the signal takeoff point 30 and the conductor 28. The resistor 31is used to compensate for the high, dark resistance of the bluephotoresistor cell, Diodes 33, 34 and 35 act as gates for the signalsfrom the different sensors. When the circuit between reference point 26and reference point 27 is unbalanced in such a way that the voltage atsignal point 30 increases as occasioned by a resistance decrease in thered photoresistor cell, the gate diode 33 will allow current to flowfrom the base of transistor 36 causing current to flow through aresistor 37, transistor 38 and transistor 39. This current is of thesame" magnitude but does cause an impedance change in the cascadedcommon collector amplifier (input several megohms, output acrossresistor 37 100 k. ohms). The current flow through resistor 37 causes avoltage distribution such that the ground end is zero and the junctionofresistor 37, transistor 38 and diode 40 is positive Diode 40 is a 15volt zener diode used to gate all signals below that potential. Adecrease in resistance of the red photoresistor cell which causes anincrease in current fiow through resistor 37 raising the voltage at thejunction of resistor 37, transistor 38 and diode 40 beyond 15 volts willcause the base'of transistor 39 to bias the transistor into conduction.Current will then flow from ground up through resistor 41, diode 42 andtransistor 39. This current flowing through resistor 41 causes thejunction of resistor 41, diode 42 and silicon control rectifier 43 tobecome positive When the voltage approaches positive 2 volts, thesilicon control rectifier will transfer into an on condition. Thesilicon control rectifier 43 circuit consists of resistor 44, the primerand resistor 45. The primer resistance is on the order of an ohm and isplaced in parallel with resistor 44. Resistor 45 is a current limitingresistor. Resistor 44 comes into play only after the primer is fired.The current through resistor 44 causes the voltage on the gate lead ofsilicon control rectifier 46 to increase and allows the silicon controlrectifier 46 to go into conduction and cause the actuation of theauxiliary circuit. The circuit of silicon control rectifier 43 andsilicon control rectifier 46 allow a delay between the primer andauxiliary actuations which may be used to advantage when a secondaryfire extinguishing system in the area is employed and its fireextinguishing agent supply taken from the same source as thatcommunicating with the supply line 14 heretofore referred to. Byreferring now to FIGURE 4 of the drawings, it will be observed that atime delay circuit used in testing the hereinbefore described circuitryto the sensor 11. is disclosed. Reference points 47 and 48 in FIGURE 3are electrically connected with reference points 47A and 48A in FIGURE 4when the time delay circuit is used. The circuit of FIGURE 4 is usedwhen a delay is needed between test and operating conditions in theactual unit associated with the control amplifier 17 as seen in FIG- URE2 of the drawings. When used and in test position current will flowthrough relay 49 charging capacitor 50. As relay 49 pulls in, contacts51 will open cutting off the voltage to the Z match amplifier, sensor 11and the control amplifier 17. Capacitor 50 feeds voltage to relay 49holding contacts 51 open until the control amplifier 17 and itsassociate control has been returned to an operating condition. Byreferring now to FIGURE 2 of the drawings, it will be observed that inaddition to the control amplifier 17 which has been hereinbeforedescribed, the circuitry includes test circuits and switches forcontrolling the same and the following operational description of thesystem will indicate their use.

When power is applied to the system by closing switch 52, a Whiteindicating light 53 is illuminated indicating the system is energized.Current will flow from ground at numbered terminal 11 on terminal strip25 through the sensor cable 18 and return to numbered terminal 10 onterminal strip 25 energizing relay 54. The lower contact of relay 54connects a lamp 55 to a 24 volt power source. A light 55 indicates thata complete sensor circuit is in service. The upper contact of relay 54(deenergized position) connects a trouble buzzer 56 to the 24 voltcircuit so that the sounding of the buzzer 56 indicates an open circuiton the sensor line. Relay 54 has an additional set of contacts 54A thatmay be used to control external power equipment in case of trouble. Whensignal lights 53 and 55 are illuminated, the system is ready foroperational test. I

Switches generally indicated at 57, 58 and 59 are multiple circuitsensor test switches. In a typical system one such switch is used foreach sensor used. The circuitry of FIGURE 2 illustrates the switches 57,58 and 59 and three sensors and it will be understood that more may beemployed. The uppermost section of the multiple circuit sensor testincludes switches 57A, 58A and 59A and these momentarily interrupt thesupply voltage to the sensors 11 and the control amplifier 17. Thisguards against false actuation due to switching transients and willautomatically reset the silicon control rectifier units 43 and 46. Thenext lower section of the switches indicated at 57B, 58B and 59Bdisconnects the control amplifier 17 from the primer circuit andconnects it to the test lamp 60., The test lamp 60 will light when thesensor 11 detects the infrared from a built-in test light or receivesvoltage from the diode depending on which is used. The next-section ofthe switches indicated at 57C, 58C and 59C connects the 24 volt powersupply to the sensor lead which connects to the built-in test light ordiode. When heat from the built-in test light falls on the photoresistorcell of the sensor 11 the voltage on the signal lead will increasecausing the control amplifier 17 to fire or gate the silicon controlrectifier 43. When this occurs, current will flow through the test lamp60, the switch 5813, the silicon control rectifier 43 and resistor 45 tothe 24 volt power supply. The illumination of test lamp 69 comprises acheck of the complete system excluding the primer and auxiliary circuit.The next lower portion of the switches 57, 58 and 59 comprises thecontacts 57D, 58D and 59D and they act to disconnect the controlamplifier 17 from the auxiliary circuit to assure against falseactuation. The switches 57, 58 and 59 are connected so that only onesensor 11 can be tested at a time.

A continuity tester for the primer and auxiliary circuit is provided andcomprises a multiple contact switch 61 including contacts 61A, 61B and61C and a meter 62. When the switch 61 is in central position the meter62 is connected to the 24 volt power supply through resistors 63 and 64and potentiometer 65. In this position the meter 62 indicates thevoltage used for continuity testing. Such voltage is set by thepotentiometer 65. Adjusting the voltage indicated on meter 62 to thesame point each time will indicate the slightest change in theresistance of the primer bridge wire or auxiliary circuits. The contacts61B and 61C connect the primer or auxiliary circuit across meter 62 andthrough the calibration potentiometer 66 or 67. In the primer position(left of center) contacts 61B and 61A connect the primer across themeter 62 as a meter shunt. A potentiometer 67 is then adjusted so thatthe meter 62 reads at mid-scale. The sensitivity of the meter 62 is suchthat any change in primer resistance will be indicated. Thus, if theprimer is open the meter 62 will read full scale. Still referring tothis portion of the system, it will be observed that there is a diode 68connected across the meter 62 in such a manner as to act as a non-linearresistor, and it therefore protects the meter 62 against burn-out. Theresistor 64 heretofore referred to acts as a current limiter for theprimer under test conditions. When switch 61 is in the auxiliaryposition (right of center) the same test conditions take place for theauxiliary as outlined for the primer. A manual switch 69 including asecondary contact 6913 provides for manual firing and is so connectedthat when it is closed the 24-volt power supply will be connecteddirectly to the primer and auxiliary circuit causing both to actuate.

An alarm light 7 0 is connected with the primer circuit in parallel sothat it will light and stay lit in case of actuation of this circuit. Torestore the system to operational condition, a reset switch 71 must bedepressed restoring silicon control rectifiers 43 and 46 to the resetcondition, the actuation of the reset switch 71 also disconnects thealarm light 70.

It will be seen that a complete description of the fire protectionsystem including the various portions thereof rendering the system ofelectromagnetic detection responding to a portion of the electromagneticspectrum has been disclosed and that an additional description of thecontinuity tests for the actuation and detection circuits connectedtherethrough has been included. Legends on the drawing in addition tothe reference numerals are referred to in the specification for aclearer understanding of the invention, its operation and its componentsand 6 it will thus be seen that a fire protection system meeting theseveral objects of the invention has been disclosed and having thusdescribed my invention, what I claim is:

1. In a fire protection system, apparatus comprising means fordelivering a fire extinguishing agent, means controlling said fireextinguishing agent delivering means and means for generating andtransmitting a trigger signal to said controlling means, said means forgenerating and transmitting said trigger signal including a controlarmplifier, electromagnetic wave sensitive photoresistors coupled tosaid control amplifier, said electromagnetic wave sensitive elementsoperable to discriminate between certain electromagnetic waves, saidcontrol amplifier including gate means coupled to said electromagneticwave sensitive elements and responsive to an unbalanced output from saidelectromagnetic wave sensitive elements, and pulse generating meanscoupled to said gate means for generating said trigger signal, saidphotoresistors responsive to portions of the electromagnetic spectrumencompassing the near infrared area.

2. The combination of claim 1 and wherein said electromagnetic wavesensitive photoresistors comprise solid state type photoconductorsresponsive to portions of the electromagnetic spectrum encompassing thenear infrared area of said electromagnetic waves.

3. The combination of claim 1 and wherein said electromagnetic wavesensitive photoresistors include three units arranged to form a voltagedivider electrically connected to said control amplifier at a signaltake-off point and wherein one of said units is responsive to the nearinfrared area of said electromagnetic waves, another portion isresponsive to the visible portion of said electromagnetic wave spectrumand a third portion arranged to n act as a compensator.

4. In a fire protection system, apparatus comprising means fordelivering a fire extinguishing agent, electronically actuated meanscontrolling said fire extinguishing agent delivering means responsive inoperation to a trigger signal and means for generating and transmittinga trigger signal to said controlling means, said means for generatingand transmitting said trigger signal comprising a solid state typephotoconductor including a red photoresistor cell, a blue photoresistorcell, and a compensating photoresistor cell responsive to the nearinfrared area of the electromagnetic spectrum, a control amplifiercoupled to said photoconductor including pulse generating means forgenerating said trigger signal and gate means including a gate dioderesponsive in actuation to said photoconductor and controlling saidpulse generating means.

5. The combination of claim 4 and wherein said control amplifierincludes a cascaded common collector circuit coupled to said gate diodeand comprising an impedance element establishing a normal potential andwherein a zener diode is coupled to said impedance element and acts togate all signals below said normal potent ial.

6. The combination of claim 4 and wherein a silicon controlled rectifieris coupled to said pulse generating means.

7. The combination of claim 4 and wherein a silicon controlled rectifieris coupled to said zener diode.

References Cited in the file of this patent UNITED STATES PATENTS2,570,280 Roifman Oct. 9, 1951

1. IN A FIRE PROTECTION SYSTEM, APPARATUS COMPRISING MEANS FORDELIVERING A FIRE EXTINGUISHING AGENT, MEANS CONTROLLING SAID FIREEXTINGUISHING AGENT DELIVERING MEANS AND MEANS FOR GENERATING ANDTRANSMITTING A TRIGGER SIGNAL TO SAID CONTROLLING MEANS, SAID MEANS FORGENERATING AND TRANSMITTING SAID TRIGGER SIGNAL INCLUDING A CONTROLAMPLIFIER, ELECTROMAGNETIC WAVE SENSITIVE PHOTORESISTORS COUPLED TO SAIDCONTROL AMPLIFIER, SAID ELECTROMAGNETIC WAVE SENSITIVE ELEMENTS OPERABLETO DISCRIMINATE BETWEEN CER-